Hair brush



FIG. 1 is a front elevational view of a hair brush, showing my new design (and also a mirror image of the rear elevational view thereof);

FIG. 2 is a side elevational view thereof (and also a mirror image of the opposite side);

FIG. 3 is a top view thereof; and,

FIG. 4 is a bottom view thereof. 

The ornamental design for a hair brush, as shown and described. 